The high-temperature oxidation of cobalt-21 wt.% chromium-3 vol.% Y2O3 alloys

Alloys of Co-21 wt. % Cr-3 vol. % Y ₂ O ₃ have been prepared by a mechanical alloying method, and oxidized in oxygen at 100 Torr in the temperature range 900–1200°C. The general effects of the dispersed oxide phase are similar to those reported for nickel-base alloys: the selective oxidation of chromium to form a continuous protective Cr ₂ O ₃ scale is promoted; the rate of growth of Cr ₂ O ₃ is reduced compared to dispersoid-free alloys; the adhesion of the Cr ₂ O ₃ is greatly improved; and the scale-forming reaction is probably at the scale-metal interface in the alloys containing the dispersoid, whereas it is at the scale-oxygen interface in dispersoid-free alloys. This last point has not been positively demonstrated. The improvement in adhesion is of particular significance, since the scales on cobalt-base alloys are prone to spallation, and it has been possible to study the mechanism of adhesion in more detail. It appears that in dispersoid-free material the metal recedes from the scale-metal interface, leaving the scale supported on the tops of metal peaks but this does not happen in the alloy containing the dispersoid, either because the growth direction of the scale has been changed, or because of changes in the substrate grain size. In general, the observations support the model proposed in an early study for the oxidation of Ni-20 wt.% Cr alloys containing oxide dispersions.This work has been supported by the Naval Air Systems Command under Contract No. N00019-71-C-0079.     

Experimental study of surface channel in insulated-gate field-effect transistor

A simple experimental technique is described for measuring the effective channel length and the surface-channel drift mobility in the insulated-gate field-effect transistor. Experimental results are presented for p channel transistors made in 8 ? cm silicon.     

The response of a hot-wire anemometer in flows of gas mixtures

An investigation of the problem of measuring turbulence quantities in flows of gas mixtures by means of hot-wire anemometry is described. In view of the lack of a reliable heat-transfer law for fine wires in flows with variable gas properties, an entirely empirical approach is adopted. Attention is paid initially to the air/carbon dioxide system and it is shown that a simple calibration procedure is possible. An assessment is made to determine a suitable gas as a marker for flows in which turbulence measurements are to be made, and it is concluded that argon is to be preferred to carbon dioxide. The procedure for measuring turbulence quantities in air/argon mixtures is discussed; the optimum arrangement is a largediameter wire operated at low overheat ratio combined with a small-diameter wire operated at high overheat ratio.     

Message from the President.

The Canadian Journal of Behavioural Science is the fourth venture in journal publication of the Canadian Psychological Association. The first was the Bulletin, a modest little quarterly which from 1940 to 1946 served the association as an embryonic scientific journal and newsletter. By 1946 the number of reports of scholarly and scientific works which it received indicated clearly that a proper scientific journal was required. Hence, in 1947 the association undertook its second, but first major journal publishing venture, the Canadian Journal of Psychology. This replaced the Bulletin. In 1950, the association established another journal to serve as a house organ and named it the Canadian Psychologist. In May 1967, the association decided that if funds could be found, a journal devoted to theory, research, and application in the areas of psychology concerned with social problems would be established and called the Canadian Journal of Behavioural Science. In January 1968 President W. H. Coons reported the gratifying news that the Canada Council had agreed to provide the needed funds. With the wholehearted support of the members of the association the Canadian Journal of Behavioural Science should soon become a sister of the Canadian Journal of Psychology of which the Canadian psychological community can be justly proud. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Space-charge-limited insulated-gate surface-channel transistor (s.c.l. i.g.f.e.t.)

Preliminary experimental results are reported on insulated-gate field-effect transistors made in high-resistivity (near-intrinsic silicon substrates. Operation occurs under space-charge-limited conditions, and maximum transconductance and minimum parasitic capacitances for this kind of device are thus obtained. Some implications for integrated monolithic microelectronics are discussed.     

Accident versus near miss causation: a critical review of the literature, an empirical test in the UK railway domain, and their implications for other sectors

An essential assumption for the usefulness of basing accident prevention measures on minor incidents is the common cause hypothesis: that causal pathways of near misses are similar to those of actual accidents (such as injuries and damages). The idea of a common cause hypothesis was originally proposed by Heinrich in his seminal book "Industrial Accident Prevention" [McGraw-Hill, New York]. In this paper, it is argued that the hypothesis of similarity of causes for major and minor accidents has become confounded with the interdependence of the ratio relationship between severity and frequency. This confounded view of the hypothesis has led to invalid tests of the hypothesis and erroneous conclusions. The evidence from various studies is examined and it is concluded that the hypothesis has not been properly understood or tested. Consequently, such a proper test was carried out using data from the UK railways which were analysed using the confidential incident reporting and analysis system (CIRAS) 21 cause taxonomy. The results provide qualified support for the common cause hypothesis with only three out of the 21 types of causes having significantly different proportions for the three consequence levels investigated: 'injury & fatality', 'damage' and 'near miss'.     

Comparing traditional and Rasch analyses of the Mississippi PTSD Scale: revealing limitations of reverse-scored items

This study examined whether Rasch analysis could provide more information than true score theory (TST) in determining the usefulness of reverse-scored items in the Mississippi Scale for Posttraumatic Stress Disorder (M-PTSD). Subjects were 803 individuals in inpatient PTSD units at 10 VA sites. TST indicated that the M-PTSD performed well and could be improved slightly by deleting one item. Factor analysis using raw scores indicated that the reverse-scored items formed the second factor and had poor relationships with normally scored items. However, since item-total correlations supported their usefulness, they were kept. The subsequent Rasch analysis indicated that five of the seven worst fitting items were reverse-scored items. We concluded that using reversed items with disturbed patients can cause confusion that reduces reliability. Deleting them improved validity without loss of reliability. The study supports the use of Rasch analysis over TST in health research since it indicated ways to reduce respondent burden while maintaining reliability and improving validity.